ABSTRACT National initiatives in precision medicine, such as the All of Us Research Program, have set ambitious plans to establish a research cohort of one million or more participants and enable a new era of medicine that empowers patients, researchers, and providers to work together toward development of individualized treatments. A central challenge to large-scaled precision medicine research is the return of individual genetic research results to study participants. Yet, approaches to scale the return of clinically actionable genetic results to large cohorts have not been well-tested to date. The magnitude of this endeavor has renewed concerns about the shortage of qualified genetic counselors for this task. Rigorous research efforts are thus needed to test the efficacy of alternate models for genetic results disclosure, which has widespread implications for how precision medicine research might yield direct benefits for study participants. We propose to conduct a randomized controlled trial (RCT) within the Black Women's Health Study (BWHS) to test alternate communication modalities for results disclosure. The BWHS is an ongoing prospective cohort study of 59,000 self-identified black women from across the United States who have been followed since 1995. Targeted sequencing of over 4000 women within the cohort for BRCA1/2 and other known or suspected high and moderate penetrance genes opens up the possibility of returning breast cancer genetic results to BWHS participants and examining the clinical utility of genetic results return. The primary aim of the proposed research project is to compare the efficacy of two communication modalities for returning breast cancer genetic research results to African American women: 1) a conventional modality that entails telephone disclosure by a licensed genetic counselor, and 2) an online self-guided modality that entails returning results directly to participants, with optional genetic counselor follow-up via telephone. Secondary aims of this study will examine 1) moderators of the intervention impact and 2) psychosocial, sociodemographic, and clinical predictors of result uptake. This study is uniquely situated to provide critical empirical evidence on the effectiveness of alternate models for genetic results return and provide further insight into the factors influencing uptake of genetic information among African American women. Study findings will inform ongoing efforts to establish scalable approaches for effective return of genetic research results, and increase access to personal health information among African American women.